Some merchants try to get around this by enforcing a minimum charge when using a credit card, but this practice is against Visa and MasterCard policy.

"According to them, it encourages customers not to use credit cards," Thompson said.

Merchants with lower average sales can negotiate to pay less per transaction, Thompson said - it just depends on the provider.

"They could lose money if you are very small volume business," Thompson said. "But it's definitely possible, and they have a lot of people doing it."

But fees aren't merchants' only concern.

The time it takes to process a credit card purchase is an issue, too.

Cash transactions are faster, said Gary Foust, owner of the Barber Pole barbershop on Bull Street.

"It cuts down on the time we spend at the register," Foust said. "Which means more people are getting served."

But that just depends on what type of terminal is being used, according to Todd Faircloth, president of merchant supplier eTransactionsPlus. Some of the new Internet Protocol terminals print tickets in two seconds.

"You can hardly make change in that time," Faircloth said.

Besides increased business, Faircloth said there are other benefits to being credit card friendly.

"These are national brands," Faircloth said. "That creates recognition for their customers."

But Miller doesn't plan on paying for that recognition anytime soon.

"It's kind of like having a partner, except you're doing all the work," Miller said.

HOW INTERCHANGE FEES AFFECT YOU

Visa, MasterCard and their member banks charge consumers a 2 percent fee on their total purchase, called an interchange fee, each time a credit or debit card is used. The companies forbid the fees from being printed on receipts. The U.S. does not regulate the fees; Australia, however, does.

Greg Parker, owner of Parker's Market, says Visa and MasterCard increased the fees twice last year and his credit card expenses were up 14 percent as a result. He also said the increased fees lead to higher gas prices.

"Today 4.1 cents out of every gallon of gas goes to credit card fees," Parker said. "It's a windfall of profits for the companies."